This invention relates to an attachment operable to accommodate a concentration measuring apparatus capable of indirectly measuring a concentration of subject matter in a human body or a plant, e.g., serum bilirubin, oxygen in the blood, blood glucose, chlorophyll, to enable direct measurement of a concentration of subject matter, and also to a concentration measuring system for directly or indirectly measuring a concentration of subject matter.
Generally, icterus, particularly severe icterus of infants may cause a death or, even if a patient can escape from a death, it may progress to nuclear icterus which causes sequelae or aftereffects such as cerebral palsy. Thus, the detection of icterus in an early stage is very crucial.
Accordingly, the icterus of a patient has been diagnosed using a concentration measuring apparatus (icterus detector) disclosed in, e.g., U.S. Pat. No. 4,267,844 without collection of blood sample. This icterus detector includes a light source for irradiating light to the skin of a human body and at least two light receiving elements for receiving light components of the reflected light from the skin in different wavelength ranges which correspond to absorptions by bilirubin pigmented in subcutaneous fat differ. The degree or stage of icterus is measured based on the outputs of the respective light receiving elements. In this way, the degree of icterus is indirectly measured by measuring the concentration of bilirubin pigmented in subcutaneous fat instead of measuring a serum bilirubin concentration.
The above icterus detector is designed to indirectly measure the degree of icterus and is used as a screening apparatus at medical institutions. For an infant supposed to have a high possibility of suffering from icterus as a result of a through-the-skin bilirubin measurement (indirect measurement), his blood is collected and a serum bilirubin concentration is accurately measured by a serum bilirubin concentration measuring apparatus. A final diagnosis is given based on this measurement result. Unlike the icterus detector, the serum bilirubin concentration measuring apparatus directly measures a serum bilirubin concentration by projecting light to the collected blood. This requires the medical institutions treating infants to be equipped with two kinds of apparatuses, increasing a burden for the necessary equipment.
Although there are a plurality of types of serum bilirubin concentration measuring apparatuses, measurement accuracy varies among these apparatuses, presenting a problem of low stability.
Under these circumstances, there have been demands from the medical institutions for an improved icterus detector which can conduct not only a through-the-skin bilirubin measurement but also for a serum bilirubin measurement, and for a concentration measuring system which can selectively conduct direct and indirect measurement of a bilirubin concentration.
Although the above description is limited to the case of measuring a bilirubin concentration, the medical institutions have similar problems and demands for measurements of oxygen in the blood, blood glucose, etc. The above problems and demands have been also found in different fields, e.g., a field of measuring chlorophyll.